Running has a ton of perks: It's free, meaning that anyone who owns a pair of sneakers (and a good bra) can do it; it's a good source of cardio; it's easy; and it can also help relieve stress. However, recent research now suggests that when it comes to endurance running, less may actually be more.
An article published last week in the Wall Street Journal cited recent research that suggests endurance running may be the exercise equivalent of eating a cheeseburger a day. The research found that despite the fact that running can lower cholesterol, improve blood pressure, and help boost overall health, those who run 30 or more miles a week may lose any advantage they have over non-runners, and in fact be at higher risk for inflammation and conditions such as atrial fibrillation or coronary-artery plaque. This doesn't mean you have to hang up your running shoes for good, though.
"I think the recent findings do encourage us to rethink the mentality that there is no upper limit to a 'safe' amount of exercise," says James Ting, M.D., sports injury specialist at Hoag Orthopedic Institute in Irvine, CA. "However, I would hesitate to define an absolute upper limit of exercise activity, as I believe that it varies between individuals and can be dependant on many factors, including their overall level of fitness as well as their underlying medical conditions."
RELATED: While not as serious as health problems, these fitness lessons learned the hard way are still good to keep in mind.
While there have been reported cases of marathon runners collapsing during races, they're actually exceedingly rare, says Larry Santora, M.D., medical director at Dick Butkus Center for Cardiovascular Wellness at St. Joseph Hospital in Orange, CA. The bigger issue, he says, is in exercisers who may have an underlying heart condition that they don't know about it until it's too late.
"There tend to be two ends of the spectrum," Dr. Santora says. "Cardiac death in a young person—say 30—is usually due to hypertrophic cardiomyopathy, a congential heart problem that tends to manifest in these years. In those 40 and older, you have more people with coronary artery disease, which happens when a sudden rupture of plaque in the artery causes a clot to form."
Additionally, most of the heart damage caused by running is reversible, so that while it's true that endurance running can cause inflammation, the benefits outweigh the risks, according to Dr. Santora.
Most people aren't endurance athletes, and the recent hype about the obesity epidemic Americans face would have you believe that too much exercise is not a problem that the U.S. is struggling with right now.
RELATED: No excuses! This 12-minute do anywhere workout will blast fat and sculpt every inch in no time.
"This shouldn't be taken as an excuse not to exercise," Dr. Ting says. "Studies have shown that individuals who exercise regularly have significantly lower rates of disability and an average life expectancy that is seven years longer than that of people who don't exercise. These findings don't dispute that; rather they raise the question of whether or not there exists a threshold beyond which excessive exercise is potentially unsafe."
In other words, everything in moderation—including exercise! If you're a relatively healthy person, there's no reason why you shouldn't be able to hit the gym or pound the pavement, but if you are worried about cardiac damage, try to avoid daily strenuous cardio activity that lasts for more than an hour, suggests Herbert Cordero, M.D., a Las Vegas-based cardiologist with HealthCare Partners. "Once or twice a week, add high-intensity interval training (HIIT) into your workout or cross-training, which is more efficient than continuous aerobic exercise training."